CN100370279C

CN100370279C - Elastical optical structure

Info

Publication number: CN100370279C
Application number: CNB018186653A
Authority: CN
Inventors: 爱德华·菲利普斯
Original assignee: Reflexite Corp
Current assignee: Ruifei America company
Priority date: 2000-11-09
Filing date: 2001-11-05
Publication date: 2008-02-20
Anticipated expiration: 2021-11-05
Also published as: US7790266B2; EP1332383B1; JP4346904B2; JP2004525393A; WO2002039148A1; US20080220217A1; US20020094417A1; AU2002225982A1; EP1332383A1; TW554175B; WO2002039148A9; CN1474947A

Abstract

A reboundable optical structure includes a base layer; and an optical element layer formed with a reboundable polymeric material and attached to the base layer. The optical structure can include a diffuser, fresnel lens, linear prism film, collimating film, lenticular elements, and retroreflective structures. A method for forming a reboundable optical structure includes providing a base layer; and attaching an optical element layer formed with a reboundable polymeric material and attached to the base layer, thereby forming an optical structure.

Description

Elastical optical structure

Background of invention

Light-diffusing film is widely used in the application of many optics, illumination and demonstration at present.Many in the most effective diffusing globe are the microstructures that adopt through design, thereby with desirable mode distribute light effectively.Great majority in these diffusers constitute by carrying out molded for a die surface a kind of polymer phase or casting, and this die surface has the embossment structure that is characterized in corresponding construction to be processed on the film surface.These structures are normally made with non-elastomeric polymer-material, such as, polyacrylate, polystyrene, polycarbonate and polyolefin.

When needed diffusion microstructure had a kind of frangible shape and also cause it to damage easily to the normal running of film in assembling process, a difficult problem had just produced.Small galled spots can cause permanent, visible cut or wearing and tearing on diffuser, thereby it can't be used in many application scenarios, has perhaps damaged its outward appearance at least.Therefore, there is a kind of like this demand, a kind of improved light-diffusing film promptly is provided.

Summary of the invention

A kind of optical texture that rebounds comprises a basic unit, and one attached to the optical element layer that constitutes in this basic unit and with the polymeric material that can rebound.This optical texture can comprise diffusing globe, Fresnel Lenses, linear prism film, alignment film, lens pillar element (lenticular elements) and retroreflective structures.The method that forms a kind of like this Elastical optical structure comprises provides a basic unit, adheres to an optical element layer that constitutes with the polymeric material that can rebound, and this optical element layer is attached in this basic unit, thereby forms an optical texture.

The present invention can be applied to diffuser, Fresnel Lenses, alignment film, linear optics structure or the like.The advantage that the present invention had is the scuffing that produces in to operation and the resistive good optical property that has simultaneously of wearing and tearing.For example, nail streaks a diffusing globe, and this diffusing globe has by acryl resin and constitutes and be of a size of about 2 optical microstructures to about 10 micron number magnitudes, and the edge of paper or nail can stay permanent vestige on this diffusing globe.In contrast, structure of the present invention can return to its prototectonics at some minutes in essence in a period of time of some hrs after being subjected to similar injury.Another advantage of the present invention is that the polymkeric substance that can rebound can stop without approval effectively optical texture is duplicated.The optical texture mould of forging can be made by the impression of optical texture, then by electroforming provide one still can but be not high-quality mould.Thisly add the industrial and commercial copy mode that occurs with duplicate and can in hard basic unit, carry out, such as acrylate copolymer.Fully pliable and tough with the optical texture that the polymkeric substance that can rebound constitutes, thus high-quality duplicating can be stoped effectively.

Description of drawings

Accompanying drawing is depicted as the light-diffusing film that can rebound.

By the more specifically description of the accompanying drawing shown in the combination to the following embodiment of the present invention, above-mentioned and other purposes of the present invention, that feature and advantage will become will be clear, and in all different views, identical part is represented with identical Reference numeral.Accompanying drawing is unnecessary to come picture according to dimension scale, and it focuses on illustrating principle of the present invention.Except that indicating in addition, all percentages and umber all are fixed by weight.

Embodiment

The present invention includes one is had the surface casting of microstructure or is molded on the desired sheet material this sheet material employing elastomeric polymer.One embodiment of the invention adopt a kind of high efficient radiation to solidify casting method, this method utilization be to obtain its flexible active casting polymkeric substance from a kind of multifunctional terminal unsaturation urethane ester oligomer (multi-functionalterminally unsaturated urethane oligomer).This polymkeric substance is the reaction product that comprises the urethane oligomer and the oxyalkylated polyvalent alcohol of terminal unsaturation isocyanates.This urethane oligomer typically forms the rebounded structure of scope in about 50% (weight) and about 90% (weight).Can rebound and be considered to when with an object collision or after contacting a kind of works and keeping one of short duration period, this works basically resilience or rebound (to spring or bounceback) for and the preceding identical shape of this contact, and can continue to keep the functional of this structure.

Suitable optical texture comprises the known diffusing screen of the industry, Fresnel Lenses, linear prism film, alignment film, lens pillar element and retroreflective structures.Diffusing screen can be used for the rear-projection screen.Diffusing screen comprises the band color or not with the whole diffusing globe of color, has the whole diffusing globe of band color of lens pillar, beaded glass screen (glass-beadedscreen) and band color surface relief diffusing globe.As shown in the figure, this optical texture 10 can comprise a basic unit 12, and this basic unit 12 can be a film.The thickness of basic unit 12 can be in the scope between about 12.5 to about 1,500 micron.This film is to be formed by polyester, polycarbonate, polyacrylate, polystyrene or other proper supporting membrane materials or their combination.This film can dye with dyestuff or pigment or becomes optical clear by methods known in the art.Optical element layer 14 is attached in the basic unit 10.This optical element layer 14 can have linear prism, column prism or other suitable elements that is used for guiding again light.This optical element layer 14 is by the material that can rebound, and forms as polyurethane, and these materials have such optical property, promptly have continuous refractive index.This polymkeric substance can not be granular, and has the uniform structure of making peace.In one embodiment, the thickness of this optical element layer arrives in about 150 microns scope about 0.15.

A case history of method that forms this polymkeric substance that rebounds is at United States Patent (USP) 5,578, and in 693, this patent was authorized people such as Hagstrom on November 26th, 1996.By using this oligomer together with a kind of high functionality modified monomer, and, this high functionality modified monomer preferably has closely knit relatively structure, the characteristic of resulting polymkeric substance can be modified, to change the balance between elasticity and rigidity, provide recovery feature at necessity of given application.In one embodiment, this modified monomer form this total polymer weight of can rebounding about 1% to about 25% between scope.In a preferred embodiment, this scope is between about 3% to about 10%.The example of modified monomer comprises two-trimethylolpropane tetra-acrylate (di-trimethylolpropane tetraacrylate), two-five erythritols, five acrylate (dipentaerythritol pentaacrylate) or their alkoxylate analog.

Bonding can as this substrate is carried out Corona discharge Treatment, perhaps be finished by using the bonding that is applied in advance on this film substrate to strengthen inter coat by the conventional method of determining.This oligomer can be regulated by the selection of (being preferably simple function) reactive diluent the bonding characteristic between the required substrate.For example, acrylate and methacrylate are suitable diluent.The example that is suitable as diluent monomer comprises (methyl) tetrahydrofurfuryl acrylate; (methyl) acrylic acid 2-ethyl phenoxy; (methyl) isobornyl acrylate; Two (methyl) acrylic acid 1,6-hexanediol ester or their alkoxylate analog.The concentration of this diluent monomer can be about 0 in about 50% scope.In one embodiment, the concentration of this diluent monomer is about 10%.

This compound can comprise other components on demand.The example of these components comprises light trigger, and its concentration arrives in about 8% the scope about 2%, hindered amine as light stabilizer, and its concentration is about 3% or lower.The example of suitable amine is two-(1,2,2,6,6-tetramethyl-4-piperidyl (piperidinyl)) sebacate.The amount of suitable hindered amine arrives in about 3% the scope about 0.Other components comprise ultraviolet light absorber, and as benzophenone or benzotriazole compound, they can improve colour fastness and stability widely.A kind of example of suitable ultraviolet light absorber is 2-(2 '-hydroxyl-3 '-5 '-a two-tertiary pentyl phenyl) benzotriazole.In addition, colorant also can add, so that tone of gray or other effects that needs to be provided.

In a preferred embodiment, a kind of multifunctional terminal unsaturation urethane ester oligomer comprises (a) a kind of urethane oligomer of terminal unsaturation isocyanates and (b) reaction product of a kind of oxyalkylated polyvalent alcohol of containing.By incorporating in the reactive chemistry metering of urethane ester oligomer of end-blocking, obtain the remarkable reduction of this oligomer viscosities with the high functionality oligomer as functionality modifier alkoxylated polyol.

The method that is used to produce these multifunctional terminal unsaturation urethane ester oligomers comprises the steps: (1) with at least a diisocyanate and the reaction of at least a polyol, and generating end group is the prepolymer of isocyanates; (2) with the acrylate or the reaction of hydroxyl-functional vinyl ether of unreacted terminal isocyanate group regiment headquarters's branch and at least a hydroxyl-functional, generate the urethane ester oligomer that contains the terminal unsaturation isocyanates; And (3) are with remaining terminal isocyanate group group and the reaction of at least a alkoxylated polyol.

A kind of radiation curing prescription contains a kind of multifunctional terminal unsaturation urethane ester oligomer, its comprise (a) a kind of contain the polyurethane of terminal unsaturation isocyanates with (b) and the reaction product of oxyalkylated polyvalent alcohol; With a kind of activated monomer.

Here employed term " the urethane ester oligomer that contains the terminal unsaturation isocyanates " is meant any urethanes that comprises a unsaturated end group and contain isocyanate groups.This unsaturated end group is preferably formed by hydroxy-functional acrylic ester and hydroxyl-functional vinyl ether.These preferred end-blocking urethane ester oligomer classes can obtain from commercial channels, and known, are respectively acrylated polyurethane and vinyl ether polyurethane.These polyurethane that contain the terminal unsaturation isocyanates are by polyisocyanate and polyol are prepared with compound (as hydroxy acrylate or the hydroxyl vinyl ether) reaction that the hydroxyl-functional of a unsaturated group is arranged.This three's reaction can in proper order or be carried out simultaneously, as the mode that routine adopted.

In a preferred embodiment, this polyisocyanate is a diisocyanate.Suitable diisocyanate comprises di-2-ethylhexylphosphine oxide (phenyl isocyanate) (also being referred to as MDI); 2, and the 4-toluene-2,4-diisocyanate (2,4-TDI); 2,4-and 2,80: 20 potpourris of 6-toluene-2,4-diisocyanate (also being referred to as TDI); 3 ,-isocyanates ylmethyl-isocyanic acid 3,5,5-trimethylcyclohexyl (IPDI); Two isocyanic acid m-tetramethyl xylene esters (TMXDI); Hexamethylene diisocyanate (HDI); And di-2-ethylhexylphosphine oxide (NSC 87419) (pressing Desmodur W sells).

Employed polyol can be polyether polyhydroxy-compound or polyester polyol.The example of polyether polyhydroxy-compound comprises poly-(epoxypropane) glycol, copolymerization (epoxy ethane-epoxy propane) glycol and poly-(tetrahydrofuran) glycol [poly (tetramethylene oxide) diols].The example of suitable polyester polyol preferably includes any known end and is two-, three-, or tetratomic polyester, for example polylactone polyester and polyester polyol, they be by dicarboxylic acid or their acid anhydrides and two-, three-, or the polycondensation reaction of tetrol prepares.

Term " acrylate of hydroxyl-functional " is meant acrylate or the methacrylate compound that is suitable for preparing and using a kind of any hydroxyl replacement of end-blocking urethane ester oligomer.These examples for compounds comprise acrylic acid 2-hydroxyethyl ester, acrylic acid 2-hydroxy-propyl ester, methacrylic acid 2-hydroxyethyl ester, three acrylic acid, five erythritol esters (PETA) and acrylic acid 4-hydroxybutyl ester.

Term " vinyl ether of hydroxyl-functional " is meant the vinyl ether that is suitable for preparing and using a kind of any hydroxyl replacement of end-blocking urethane ester oligomer.The example comprises glycol monomethyl vinyl ether and cyclohexanedimethanol mono vinyl ether (cyclohexane dimethanol monovinyl ether).

The propoxylate (can buy with THANOL LS 490) of the ethoxylate that this polyfunctionality modifier can be nominal 6 mole of trimethylol propane (can buy with MACOL RD 306EM) and 12 moles of D-sorbites of nominal from PPG Industries from Eastman ChemicalCo..Equally, these just are used for explaining, any functionality can be considered to be used greater than 2 alkoxylated polyol.

Molecular weight depends on specific polyol, polyisocyanate and their ratio, and specific multifunctional modifier.Usually, the number-average molecular weight of this multifunctional terminal unsaturation urethane ester oligomer can arrive in about 10,000 the scope about 1,500, does not consider chain elongation.

An embodiment preferred relates to a kind of urethane ester oligomer of end-blocking, and it comprises following combination: (a) at least a diisocyanate, its equivalent are about 80 to about 200; (b) at least a polyol, its equivalent are about 100 to about 2,000; (c) at least a hydroxy acrylate or hydroxyl vinyl ether; And (d) at least a oxyalkylated polyvalent alcohol, its equivalent is about 32 to about 200.

This embodiment preferred is based on the performance of improved oligomer, promptly by the functionality of the urethane ester oligomer of end-blocking is brought up to greater than 2 officials can but less than 6 officials can, simultaneously, compare with the conventional method of being put down in writing, reduce viscosity.This method also has an advantage, is exactly isocyanates, and any potpourri of hydroxy acrylate or hydroxyl vinyl ether and polyol can be used for reaching the final performance of this curable materials.By adopting the stoichiometry of oxyalkylated polyvalent alcohol adjustment reaction, the viscosity of this urethane oligomer is minimized.

By by oxyalkyl units (as, EO or PO group) should functional modified dose (promptly, polyvalent alcohol, as TMP or D-sorbite) from hithermost urethane groups, separate, and the functionality of the oxyalkylated polyvalent alcohol of this modification is brought up to greater than 2, with similar TMP or D-sorbite product and do not have EO or PO group by comparison, realized the remarkable reduction of oligomer viscosities, and do not influenced other performances conversely.And, by improving the functionality of this modifier, the content of the urethanes of polyhydroxy molecule also improved (as, replace TMP with D-sorbite, for example, the number of the urethane groups in the above-mentioned oligomer has been brought up to about 24).

Can form heat curing by free radical, for example use superoxide, perhaps, alternatively, according to the radiation curing of the conventional method of radiation curing, comprise methods such as adopting ultraviolet ray or beam energy,, terminal unsaturation urethane ester oligomer multifunctional to this is cured.Usually, these multifunctional terminal unsaturation urethane ester oligomers can use separately, perhaps, as the principal ingredient of radiation-curable composition, together with other components, use together as activated monomer, crosslinking chemical and light trigger.Preferably, the concentration of these multifunctional terminal unsaturation urethane ester oligomers in this radiation curable composition about 20% in the scope of about 100% (weight), more preferably about 50% in the scope of about 100% (weight).

Activated monomer also is referred to as active solvent, also may reside in these radiation curable compositions.Usually, any activated monomer that is suitable for conventional radiation curable composition can use with this multifunctional terminal unsaturation urethane ester oligomer.This class active solvent is preferably acrylate or methacrylate.The concentration of the activated monomer in radiation curable composition can arrive in the scope of about 40% (weight) about 0%, preferably arrives in the scope of about 20% (weight) about 0%.Can also comprise conventional crosslinking chemical and light trigger in this radiation curable composition.Based on the general assembly (TW) of this radiation curable composition, the concentration of each of these type components preferably can be about 0% in about 30% scope.

This radiation curable composition can also comprise a spot of conventional additives, as pigment, and wetting agent, and like that, they are to use according to common known effective concentration.

This radiation curable composition can prepare by the method for routine, that is, selected component is mixed together.Said composition can put on substrate by the mode of routine, and these modes comprise that spraying, heavy curtain are coated with, soak pad (dip pad), roller coat and brushing process.Said composition can be applied in any acceptable substrate, as glass, plastics or the like.In a preferred embodiment, said composition can be applied on the film of formation such as polyester, polycarbonate, polyacrylate, then, said composition is cast film forming in mould, and composition is by pressure rolling (pressure nipped).

The radiation curable composition that is applied in can pass through any known photochemical radiation curing, as exposes to the open air in ultraviolet ray, x-light, α particle, electron beam or gamma-ray method and solidify.Radiation can use any known or usually available that class radiation curing equipment carry out, for example, curing can by means of low, in or high pressure mercury arc lamp carry out.Curing can be in air or at inert atmosphere, as carrying out in nitrogen or the argon.

Solidify some variation of the required exposure time of said composition along with the variation of the thickness of the type of specific prescription, radiation and wavelength, flux of energy and film.The technician in radiotechnology field can determine the appropriate curing time of any particular composition.Usually, this set time is quite short, that is, and and less than about 1 minute.In one embodiment, the ultraviolet curing radiation can be about 157-236 watt/centimetre (400-600 a watt/inch), presses ultraviolet light source in the use.

Claims

1. optical texture that can rebound comprises:

A) basic unit; With

B) a kind of radiation curable composition, when being fashioned into optical element layer with micromechanism surface and being solidified by photochemical radiation, described radiation curable composition forms attached to the rebounded polymeric material in the basic unit.

2. the optical texture that rebounds as claimed in claim 1, wherein, described optical texture is selected from by the diffuser diffusing globe, Fresnel Lenses, linear prism film, retro-reflection element, the group that lens pillar element and alignment film are formed.

3. the optical texture that rebounds as claimed in claim 1, wherein, described basic unit comprises and a kind ofly is selected from polyester, polycarbonate, polyacrylate and polyolefinic a kind of polymkeric substance, or their combination.

4. the optical texture that rebounds as claimed in claim 1, wherein, the described polymeric material that rebounds comprises polyurethane.

5. the optical texture that rebounds as claimed in claim 4, wherein, described polyurethane is formed by a kind of multifunctional terminal unsaturation urethane ester oligomer.

6. the optical texture that rebounds as claimed in claim 4, wherein, described polyurethane is to be formed by a kind of urethane oligomer and a kind of alkoxylated polyol that comprises the terminal unsaturation isocyanates.

7. the optical texture that rebounds as claimed in claim 1, wherein, the described polymeric material that rebounds comprises a kind of multifunctional terminal unsaturation urethane ester oligomer, and this multifunctional terminal unsaturation urethane ester oligomer is from a kind of reaction product that comprises urethane oligomer and a kind of alkoxylated polyol of terminal unsaturation isocyanates.

8. the optical texture that rebounds as claimed in claim 1, wherein, the described polymeric material that rebounds comprises a kind of thinning agent.

9. the optical texture that rebounds as claimed in claim 8, wherein, the described polymeric material that rebounds comprises a kind of being selected from by comprising (methyl) tetrahydrofurfuryl acrylate; (methyl) acrylic acid 2-ethyl phenoxy; (methyl) isobornyl acrylate; Two (methyl) acrylic acid 1, a kind of thinning agent of the group that the monomer of 6-hexanediol ester or their alkoxylate analog is formed.

10. the optical texture that rebounds as claimed in claim 1, wherein, the described polymeric material that rebounds comprises acrylate and methacrylate.

11. the optical texture that rebounds as claimed in claim 1, wherein, the described polymeric material that rebounds comprises a kind of light trigger.

12. the optical texture that rebounds as claimed in claim 1, wherein, the described polymeric material that rebounds comprises a kind of hindered amine as light stabilizer.

13. the optical texture that rebounds as claimed in claim 1, wherein, the described polymeric material that rebounds comprises a kind of ultraviolet light absorber.

14. the optical texture that rebounds as claimed in claim 1, wherein, the described polymeric material that rebounds comprises one at about 0.15 thickness that arrives in about 150 micrometer ranges.

15. the method for the optical texture that a formation can be rebounded comprises:

A) provide a basic unit;

B) radiation curable composition is applied in the described basic unit;

C) radiation curable composition that will be used fashions into the optical element layer with micromechanism surface; And

D) radiation curable composition that will be moulded by photochemical radiation solidifies, thereby forms optical texture.

16. as the method for claim 15, wherein, this polymeric material that can rebound is to solidify by exposing to the open air under a kind of radiation in the group of being made up of ultraviolet ray, x-light, α particle, electron beam and gamma-rays.